The development of Amadumbe (Colocasia esculenta (l.) schott)-soya composite biscuits with improved nutritional and sensory properties

The Amadumbe crop [Colocasia esculenta (L.) Schott] is a traditional Southern African tuber crop which is rich in starch, mucilage and micronutrients. Amadumbe tubers have limited amount of proteins and as a result, amadumbe-processed foods lack adequate protein. The purpose of this study was therefore to develop protein-rich amadumbe-soya composite biscuits, which would be acceptable to consumers. Biscuits were prepared by combining amadumbe and soya flours at ratios: 90:10, 70:30 and 50:50. Functional properties of composite flours and the physical properties of composite biscuits were determined. The proximate composition, amino acid composition and protein digestibility of composite biscuits were determined. Consumer acceptability test of biscuits was performed using nine-point hedonic scale. The results indicated that the 90% amadumbe and 10% soya composite biscuits had high significant values of moisture, ash, carbohydrates contents and energy values. The 50% amadumbe and 50% soya composite biscuits had significantly high values of fat, crude protein contents and acid detergent fibre (ADF). The protein digestibility, amino acid contents, especially the lysine contents of composite biscuits increased significantly (p ≤ 0.05) with an increase in the percentage of soya. The mineral contents of composite biscuits; Ca, Mg, P, Zn, Cu, Mn and Fe increased significantly (p ≤ 0.05) with the increase of soya in the composite biscuits. There was a significant difference in the mean taste acceptability and mean overall acceptability when the soya concentration was increased to 50%. Soya was successfully used to produce amadumbe composite biscuits with better nutritional quality with respect to protein content, amino acid profile and selected mineral contents and which were acceptable to consumers.National Research Foundation (South Africa)Life and Consumer ScienceM.Sc. (Agriculture

Physicochemical and Sensory Evaluation of Grain-Based Food

Consumers are increasingly demanding more sources of plant-based nutrition, and the food industry is responding by developing novel foods with grain-based ingredients. These products include dairy, egg and meat alternatives. Notably, in order for the production of these foods to be viable, the sustainability of the supply chain must improve and the product price must be lowered. Therefore, upcycling of grains by-products has been considered. However, the functionality and acceptability of functional foods made with upcycled ingredients from legumes and grains must be tested to ensure consumer compliance. This Special Issue of Foods aims to present the latest research on the physicochemical and sensory evaluation of plant-based alternatives to dairy, eggs and meat made with grains. Product categories include beverages, fermented beverages, dressings, bakery items and plant-based meats. Ingredients considered include, but are not limited to, protein concentrates and isolates, fibres, starches and enzymes. Particular emphasis will be given to potential applications of upcycled ingredients such as legume water (Aquafaba, Liluva), by-products of the starch industry (protein, fibre) and protein isolation (starches). Physicochemical evaluation encompasses determination of the functionality of ingredients (foaming, emulsifying and thickening), texture analysis, rheology (viscosity, pasting properties), thermal properties (thermogravimetric analysis and differential scanning calorimetry), water mobility (nuclear magnetic resonance) and image analysis. Sensory evaluation includes both trained panels and consumer preference

Tiger nut powder as ingredient for obtaining gluten free foods based on noodle processing and extrusion technology

Tiger nut (Cyperus esculentus L.) is a sweet tuber mostly cultivated in Eastern Spain (Valencia) and in west Africa. Its nutritional profile stands out for the high fiber and unsaturated fat content; moreover, the moderate protein amount might make it suitable for the nutritional enrichment of gluten free foods. The objective of this thesis was to extend the applications of tiger nut as gluten free (GF) ingredient in noodles making and snacks. The study of marketed GF pasta revealed the nutritional inadequacy and lower cooking performances compared with their gluten containing homologous. The quantification of furosine content was handy for a better understanding of the heat damage caused during the production process. At this point, tiger nut flour was utilized for the design of gluten free noodles. The effect on noodles physicochemical characteristics leaded by different hydrocolloids (guar gum, xanthan gum, inulin and carboxymethyl cellulose) and by differing hydration levels revealed the importance in the selection of the most appropriate strengthening agent. Specifically, samples with 0.5% xanthan gum and adjusted hydration level exhibited the best cooking behavior and high final firmness. Owing to the growing extruded snacks success, tiger nut flour was blended with rice and soluble fiber to evaluate its technological adequacy for the extrusion-cooking process. Apparent viscosity, structural and surface characteristics of the gluten free snacks were deeply influenced by tiger nut addition. An improving of the nutritional profile, total soluble phenolics content and the total antioxidant capacity were found in the samples with tiger nut. Overall, it was possible to obtain GF foods containing tiger nut powder by applying different processing alternatives.Tiger nut (Cyperus esculentus L.) is a sweet tuber mostly cultivated in Eastern Spain (Valencia) and in west Africa. Its nutritional profile stands out for the high fiber and unsaturated fat content; moreover, the moderate protein amount might make it suitable for the nutritional enrichment of gluten free foods. The objective of this thesis was to extend the applications of tiger nut as gluten free (GF) ingredient in noodles making and snacks. The study of marketed GF pasta revealed the nutritional inadequacy and lower cooking performances compared with their gluten containing homologous. The quantification of furosine content was handy for a better understanding of the heat damage caused during the production process. At this point, tiger nut flour was utilized for the design of gluten free noodles. The effect on noodles physicochemical characteristics leaded by different hydrocolloids (guar gum, xanthan gum, inulin and carboxymethyl cellulose) and by differing hydration levels revealed the importance in the selection of the most appropriate strengthening agent. Specifically, samples with 0.5% xanthan gum and adjusted hydration level exhibited the best cooking behavior and high final firmness. Owing to the growing extruded snacks success, tiger nut flour was blended with rice and soluble fiber to evaluate its technological adequacy for the extrusion-cooking process. Apparent viscosity, structural and surface characteristics of the gluten free snacks were deeply influenced by tiger nut addition. An improving of the nutritional profile, total soluble phenolics content and the total antioxidant capacity were found in the samples with tiger nut. Overall, it was possible to obtain GF foods containing tiger nut powder by applying different processing alternatives

The effect of extrusion on the nutritional, functional and structural properties of gluten-free extruded snacks fortified with whey protein concentrate and cowpea flour : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University

Rising health concerns along with changes in lifestyles and diets have increased the demand for ready-to-eat snacks with increased the protein, fibre, and bioactive compounds through extrusion processing across the globe. Therefore, this study focused on determining the technical feasibility of adding varying levels of cowpea and whey protein concentrate (WPC) to rice flour to produce extruded snacks and assess the impact of extrusion processing and fortifications of cowpea and WPC on the nutritional and physicochemical properties. Further, the effect of fortifications of cowpea and WPC on textural and sensory properties of rice-based snacks was evaluated. This research also extended to investigate more nutritional aspects of cowpea flour during germination under different LED lights. Rice flour was blended with cowpea flour and WPC at weight ratios of 90:10:0, 80:15:05, 70:20:10, 60:25:15, and 50:30:20 to prepare composite flours. Rice flour was used as a control. The effects of different levels of cowpea flour and WPC additions on the nutritional components, pasting properties, in vitro starch and protein digestibility of rice-based blends were investigated. Results indicated that the peak, breakdown, setback, and final viscosities were significantly lower, and the pasting temperature was significantly higher with cowpea and WPC fortifications compared to the control. The observed total reduction in reducing sugars being released during the in vitro starch digestion for the extruded samples was in the range of 14-41% at the inclusion levels of 10-30% CP and 5-20% of WPC, respectively. An increase in the ratio of cowpea flour and WPC increased the protein and fibre contents and decreased the starch content of raw blends. The increased protein content had an impact on protein digestibility. Raw blends were extruded using a Clextral twin-screw extruder with co-rotating and intermeshing screws. The processing conditions used a die temperature of 111.5 °C, a screw speed of 252 rpm, a feed rate of 7.98 kg h-1, a water rate of 90.67 kg h-1, and a die diameter of 3 mm. Nutritional, physicochemical, and textural properties of the extrudates were evaluated. The protein and fibre contents of the extrudates significantly increased (p<0.05) with cowpea (10-30%) and WPC (5-20%) fortifications compared to those of the control. Increased cowpea and WPC contents decreased lightness and increased the bulk density and hardness of the extrudates. The crispiness associated with the number of peaks during the compression test increased with higher levels of cowpea and WPC. Correlation analysis revealed that the protein and fibre contents were significantly correlated to hardness, crispiness, bulk density, water absorption index and colour properties of the extrudates. The essential and non-essential amino acid contents increased proportionally to the increases of the cowpea and WPC fortifications in the extrudates. Extrusion increased the oligosaccharides (2-3-fold) and resistant starch (1-3-fold) contents, whereas the insoluble fibre content was not significantly affected. Extrusion increased the protein digestibility (p˂0.05) and amino acid composition in the snacks. Extruded and raw samples enriched with cowpea and WPC had an increase in the total phenolic content (TPC) and antioxidant activity. Extrusion significantly reduced the TPC, and antioxidant properties of the extruded snacks compared to their raw counterparts. The observed total reduction of released reducing sugars during the in vitro digestion was in the range of 14-41% at the inclusion levels of 10-30% cowpea flour and 5-20% of WPC, respectively. After the in vitro digestion process, the antioxidant activity of the cowpea and WPC fortified snacks was more than 2-fold higher compared to their extruded counterparts. The effects on sensory properties of cowpea and WPC fortification in rice-based ready-to-eat extruded were investigated. Six samples of extruded snacks were evaluated by the 70 consumers for acceptability using a 9-point hedonic scale. The sensory properties were assessed using the check-all-that-apply (CATA) method and the just-about-right (JAR) scale. The cowpea and WPC fortified samples had higher scores for overall liking than the control sample made with 100% rice flour. The 15-25% cowpea and 5-15% WPC fortified samples had the highest JAR frequencies in the penalty analysis for colour and texture attributes. According to Cochran’s Q test, panellists were able to discriminate different textural attributes, being the terms soft and crunchy terms significant for the extrudates. Overall, the analysis of all sensory attributes demonstrated that the formulation of 15% cowpea and 5% WPC had a higher acceptance by the consumers involved in this study. A principal component analysis (PCA) revealed that there were positive associations between crispiness and L* value, and hardness b* and a* values, respectively. The final experiments were extended to investigate more extensively about nutritional properties of cowpea flour during germination under different LED light conditions. Light quality and intensity are vital for plant development and pigment biosynthesis. The effects of a dark condition and various light-emitting diodes (LEDs), such as red, blue, and white fluorescent lamps were evaluated on the nutritional components, mineral content, levels of phenolic compounds and antioxidant activities of cowpea sprouts. The protein and total dietary fibre concentrations of the cowpea sprouts increased significantly with the application of blue and red LED lights compared to the dark condition. The phytic acid, trypsin inhibitory activity, raffinose series oligosaccharides and starch fractions of cowpea sprouts germinated under the light conditions were not significantly different from those germinated under the dark conditions. The total phenolic and antioxidant properties of cowpea sprouts under the white and red LED lights were significantly higher when compared to that of the blue and dark environments. The red LED grown cowpea sprouts had the highest mineral content followed by the white, blue, and dark conditions, respectively. These results show the potential beneficial use of cowpea and WPC, as functional ingredients to improve the nutritional profile and reduce the glycaemic index of rice-based extruded snacks. In the cowpea sprouts study, the application of red LED light and white fluorescent light sources improved the nutritional, total phenolic content, and antioxidant properties of cowpea sprouts. This experiment confirmed the recent findings on the beneficial effects of LED light on plant growth and quality of the crops, including the accumulation of phytonutrients in sprouts. Incorporation of natural phytonutrients rich foods in the human diet in different ways exert beneficial effects for human health

Efecto de la sustitución de harina de trigo por harinas de chía (Salvia hispanica L.), Amaranto (Amaranthus caudatus) y Quinoa (Chenopodium quinoa) en las propiedades nutricionales, tecnológicas y sensoriales de un producto panario precocido y congelado

Los hábitos alimentarios de los consumidores han cambiado progresivamente en las últimas décadas, buscando una alternativa de alimentos con alto valor nutricional e impacto en la salud. En ese sentido, los productos panarios son clave en la dieta y poseen potencial para ser adicionados con ingredientes nutritivos y saludables. Sin embargo, esto presenta un desafío tecnológico debido a la inclusión de ingredientes carentes de gluten, además de cumplir con las expectativas de los consumidores en cuanto a características de producto fresco con el mismo valor nutricional/funcional a pesar de no ser elaborado en el día. Para ello, la tecnología de elaboración de productos panarios precocidos y congelados asegura la disponibilidad del producto a cualquier hora del día. En este sentido, las harinas integrales de amaranto (Amaranthus caudatus, Amranthus spinosus y Amaranthus hypochondriacus), quínoa (Chenopodium quinoa) y/o semillas de chía (Salvia hispanica) y sus harinas integrales y desengrasadas, tras la extracción del aceite, son las materias primas investigadas en este estudio para ser incorporadas a formulaciones panarias por ser ingredientes con alto valor nutricional. Para ello, se determinó el nivel máximo de sustitución de harina de trigo por los nuevos ingredientes teniendo en cuenta la conservación de la calidad tecnológica, un mayor aporte nutricional y la aceptabilidad por parte de los consumidores. Con esta información se desarrolló una formulación optimizada con la inclusión de harinas integrales de amaranto, quínoa y chía, utilizando un diseño factorial (19% amaranto; 4% quínoa y 10 % chía). Este producto panario, con solo un 33 % de sustitución de harina, presentó mejores características tecnológicas, nutricionales y sensoriales que un producto integral de trigo. El proceso de precocido/congelado/almacenamiento en congelación no mermó de manera significativa sus características tecnológicas, a excepción de algunos parámetros de textura, conservando su valor nutricional. La ingesta de este producto optimizado con mayor contenido de fibra, proteínas de alto valor biológico, ácidos grasos insaturados, mayor contenido de minerales y menor índice glucémico podría contribuir a la prevención del desarrollo de enfermedades precedidas por el síndrome metabólico. Las harinas sustitutas alternativas propuestas en esta investigación podrían incrementar sustancialmente el valor nutricional y funcional de alimentos a base de cereales a bajos porcentajes de sustitución.Consumers eating habits have progressively changed in recent decades, seeking an alternative food with high nutritional value and impact on health. In this sense, bread products are key in the diet and have the potential to be added with nutritious and healthy ingredients. However, this presents a technological challenge due to the inclusion of gluten-free ingredients, along with meeting consumer expectations regarding fresh product characteristics with the same nutritional/functional value despite not being made on the same day. Therefore, the technology for making pre-cooked and frozen bread products ensures the availability of the product at any time of the day. In this sense, the wholemeals of amaranth (Amaranthus caudatus, Amranthus spinosus and Amaranthus hypochondriacus), quinoa (Chenopodium quinoa) and/or chia seeds (Salvia hispanica) and their wholemeal and defatted flours, after extracting the oil, are the raw materials investigated in this study to be incorporated into bakery formulations as they are ingredients with high nutritional value. For this, the maximum level of substitution of wheat flour by the new ingredients was determined, taking into account the conservation of technological quality, a greater nutritional contribution and acceptability by consumers. With this information, an optimized formulation was developed with the inclusion of wholemeal amaranth, quinoa and chia flours, using a factorial design (19% amaranth; 4% quinoa and 10% chia). This bread product, with only 33% flour substitution, presented better technological, nutritional and sensory characteristics than a whole wheat product. The pre-cooked/frozen/frozen storage process did not significantly reduce its technological characteristics, with the exception of some texture parameters, preserving its nutritional value. The intake of this optimized product with a higher fiber content, high biological value proteins, unsaturated fatty acids, higher mineral content and lower glycemic index could contribute to the prevention of the development of diseases preceded by metabolic syndrome. The alternative substitute flours proposed in this research could substantially increase the nutritional and functional value of cereal-based foods at low substitution percentages

Viscoelasticity

This book contains a wealth of useful information on current research on viscoelasticity. By covering a broad variety of rheology, non-Newtonian fluid mechanics and viscoelasticity-related topics, this book is addressed to a wide spectrum of academic and applied researchers and scientists but it could also prove useful to industry specialists. The subject areas include, theory, simulations, biological materials and food products among others

Nutritional and functional properties of porridges from extrusion cooked cassava-soy composite with wheat bran or grape pomace

Diet related non-communicable diseases such as obesity and type-2 diabetes are on the rise in sub-Saharan Africa. The rise is related to an increasing demand for highly refined and convenience-type foods with a decline in consumption of whole grains and high fibre foods. Dietary fibre can be incorporated into locally available food crops using extrusion cooking to produce instant food products with improved nutritional and functional properties. This study therefore investigated the effect of extrusion cooking and wheat bran or grape pomace addition on the nutritional, functional and sensory properties of a cassava- soy composite. Grape pomace or wheat bran was added at 0, 10 and 20% levels to a cassava- soy composite and extrusion cooked. The composites with and without grape pomace or wheat bran were analysed for proximate composition, water absorption and solubility index, in-vitro starch digestibility (IVSD), soluble and insoluble dietary fibre content, in-vitro protein digestibility (IVPD), nitrogen solubility index, flow properties, total phenolic content and, anti-oxidant property. Descriptive sensory properties, oral processing characteristics and satiety of porridges with and without wheat bran were determined. Extrusion cooking led to a decrease in IVPD and nitrogen solubility index of all composites. The high temperature in the extruder may have facilitated formation of covalent and non-covalent interactions between soy proteins and other food components which led to reduction in nitrogen solubility index and IVPD. Extrusion cooking led to an increase in starch digestibility of the composites compared to unextruded samples. The addition of either grape pomace or wheat bran lowered starch digestibility and estimated glycaemic index of composites. The high viscosity of composites with wheat bran may be responsible for the decrease in starch digestibility observed. High viscosity may retard enzyme diffusion to substrate for digestion and slow down the release and transit of hydrolysis products towards the absorptive surface of the mucosa. The phenolics present in grape pomace may have prevented the formation of an enzyme-substrate complex thus, lowering starch digestibility of composites which contained grape pomace. There was an increase in soluble dietary fibre content and a decrease in insoluble dietary fibre content of all composites after extrusion cooking. High shear in the extruder may have facilitated fragmentation and depolymerization of insoluble dietary fibre. All porridges showed shear thinning behaviour. Composites with 20% wheat bran had a higher apparent viscosity compared to the other composites. This may be due to solubilization of insoluble dietary fibre during extrusion cooking and this could be related to the decrease in IVSD and estimated glycaemic index observed in this composite. In contrast, lower apparent viscosity was observed in the composites with grape pomace upon extrusion cooking. It is possible that despite the increased solubilization of insoluble dietary fibre after extrusion cooking, the molecular weight of the soluble dietary fibre portion was low and could not promote viscosity. Although, grape pomace addition to cassava-soy composite increased the total phenolic content and anti-oxidant activity of composites, extrusion cooking decreased the total phenolic content and anti-oxidant activity of composites. Sensory attributes such as visually perceived viscosity, presence of particles, coarseness and thickness were strongly perceived in the composite with 20% wheat bran. The addition of wheat bran reduced the cassava aroma and glossiness of composite porridges. The composite porridge with 20% wheat bran was eaten with a higher number of bites, required a longer oral processing time and total meal duration compared with porridge without wheat bran. The subjective satiety responses post ingestion of the porridges also showed the composite porridge with 20% wheat bran led to greater reduction in hunger, an increase in fullness, a decreasing desire to eat and lower prospect to consume another meal compared to the other porridges. In conclusion, the results from this research demonstrate that extruded instant composites of cassava-soy flour with grape pomace or wheat bran have lower starch digestibility and estimated glycaemic index compared to composites without wheat bran or grape pomace. Changes in the functional properties of dietary fibre during extrusion cooking is largely responsible for the improved nutritional and sensory properties of extrudates. Thus, grape pomace or wheat bran have great potential to be incorporated as dietary fibre sources in starch-rich foods with the use of extrusion cooking to produce instant food products suitable for the management of diet-related diseases such as type-2 diabetes.Thesis (PhD)--University of Pretoria, 2017.Food SciencePhDUnrestricte

INTSORMIL 2000 Annual Report

Presently, worldwide, more than 800 million people are hungry and over I billion are desperately poor, and food demand is increasing rapidly. The majority of poor live in rural areas in developing countries and agricultural and food systems development is vital to economic growth; improving environmental quality; strengthening nutrition, health and child survival; improving the status of women; and promoting democratization. It is estimated that by 2000, the number of people living in developing countries will grow from 4.9 billion to 6.8 billion people. More than 1.3 billion people today live on less than one dollar per day. It is estimated that the number of hungry people will exceed one billion by 2020. The global population of underweight children below age five is expected to increase from 193 million in year 2000 to over 200 million in year 2020. Increased production of cereals, which are crucial sources of food energy and other nutrients, is necessary to reduce world hunger. Sorghum and millet are two major cereal grains, particularly in semi-arid regions of the world. In 1999,65.8 million metric tons (MT) of sorghum were produced worldwide, of which 19.7 million MT were produced in Africa, mainly for direct consumption by humans, and 14.7 million MT were produced in the United States, mainlyfor livestock feed to produce meat for human consumption. In the crop year 1997-1998, the United States exported 5.3 million MT of grain sorghum mainly for livestock feed, and in 1998, U.S. grain sorghum exports were worth $531 million. Large areas are planted to sorghum each year. For example, in 1999 sorghum was produced on 44.8 million hectares (ha, or 173,036 square miles, [sq mi]) worldwide, 23 million ha (88,728 sq mi) in Africa, and 3.4 million ha (13,278 sq mi) in the United States. About 500 million people worldwide depend upon sorghum for food, and most of these people are in developing countries where droughts and famine are common occurrences. Clearly, sorghum production and utilization as food and feed are vitally important to developing countries and to the United States

INTSORMIL 2000 Annual Report

Presently, worldwide, more than 800 million people are hungry and over I billion are desperately poor, and food demand is increasing rapidly. The majority of poor live in rural areas in developing countries and agricultural and food systems development is vital to economic growth; improving environmental quality; strengthening nutrition, health and child survival; improving the status of women; and promoting democratization. It is estimated that by 2000, the number of people living in developing countries will grow from 4.9 billion to 6.8 billion people. More than 1.3 billion people today live on less than one dollar per day. It is estimated that the number of hungry people will exceed one billion by 2020. The global population of underweight children below age five is expected to increase from 193 million in year 2000 to over 200 million in year 2020. Increased production of cereals, which are crucial sources of food energy and other nutrients, is necessary to reduce world hunger. Sorghum and millet are two major cereal grains, particularly in semi-arid regions of the world. In 1999,65.8 million metric tons (MT) of sorghum were produced worldwide, of which 19.7 million MT were produced in Africa, mainly for direct consumption by humans, and 14.7 million MT were produced in the United States, mainlyfor livestock feed to produce meat for human consumption. In the crop year 1997-1998, the United States exported 5.3 million MT of grain sorghum mainly for livestock feed, and in 1998, U.S. grain sorghum exports were worth $531 million. Large areas are planted to sorghum each year. For example, in 1999 sorghum was produced on 44.8 million hectares (ha, or 173,036 square miles, [sq mi]) worldwide, 23 million ha (88,728 sq mi) in Africa, and 3.4 million ha (13,278 sq mi) in the United States. About 500 million people worldwide depend upon sorghum for food, and most of these people are in developing countries where droughts and famine are common occurrences. Clearly, sorghum production and utilization as food and feed are vitally important to developing countries and to the United States